Recent Developments in Hermetic Storage Technology Using Sealed Flexible Storage Structures

摘要

Restrictions due to the adverse effects of pesticide residues in food and the environment have resulted in the imposition of strict limitations on pesticide registration by regulatory agencies. Consumer demand for chemical-free and insect contamination-free products has increased the attention for the application of non-residue organic technologies for the protection of stored grain. Among the new gaseous application technologies that have successfully replaced fumigants are the production of modified atmospheres (MAs) through the use of biogenerated MAs,for insect control and for quality preservation of seeds, stored paddy, polished rice, wheat, pulses, coffee beans, cocoa beans, and high moisture com. Biogeneration takes advantage of the atmospheric gas composition produced by the respiratory metabolism of the biological agents of the grain bulk which prevents insect development and suppresses microflora activity. Sufficiently sealed structures enable insects and other aerobic organisms in the commodity,and/or the commodity itself,to generate an MA by reducing the O2 and increasing the CO2 concentrations. Freshly harvested high moisture corn has been successfully stored under hermetic conditions, maintaining its quality prior to subsequent drying or processing into feeds or ethanol. A recent development is the use of MAs in a low-pressure environment or use of COs to accelerate the process. These niche applications of MAs have resulted in very promising treatments with market acceptability.As discussed and illustrated,hermetic storage for dry commodities is now used in 31 countries for storage of a number of important commodities. The growing number of types of hermetic containers for various applications is documented. This ranges from small portable containers of 60 kg to 1 tonne, called SuperGrainbagsTM, to a series of large flexible storage structures, called CocoonsTM, TranSafelinersTM and BunkersTM, ranging from 5 tonne to 30 000 tonne capacity. Economic analysis as reported by studies and field trials is provided for representative applications, including rice and cocoa.